Electric snap switch



June 10, 1930 J. H. NELSON 2,7 I C ELECTRIC SNAP SWITCH 7 Filed May 5, 1928 atented June 1%, E

- JOHN H. NELSON, or CHICAGO, ILLINOIS, ASSIGNOR T nann A. nonenasgon I nnonson, MICHIGAN nLnc'rRIo snaiswI'rcII Application filed May 5,

contractible resilient member and an abut-" 1o ment against which one end of said member presses, one of the mutually engaging surfaces of said two elements being extendedand along which the other member may slide, the element having said surface being.

adjustable to cause its said surface to be obtuse to the line of pressure of said resilient member to enable quick expansion of said member and to occupy an alternative position to effect another adjustment of said member, whereby the switch may be snapped into at least one of its circuit controlling adjustments. In thepreferred embodiment of the invention, said abutment is provided with the extended surface, the abutment, as

a whole, being adjustable to change the direction of the surface as described. This abutment is desirably so adjustable as to cause its said surface to be obtuse to the line .of pressure of the resilient member upon 0 opposite sides of said resilient member so that the switch may not only be snapped open but mag also be snapped closed.

The inventlon will be more fully explained in connection with the accompanying drawing in which Fig. l-is a longitudinal sectional view of the preferred embodiment of the invention showing the switch in a circuit'closing adjustment, some parts appearing in elevation; Fig. 2 is a sectional view.

on line 2-2 of Fig. 1; Fig. 3 is a sectional view on line 3-3 of Fig. 1; Fig. 1 is a view .somewhat similar to Fig. 1 but omitting some of the parts and showing more parts in elevation and also indicating the switch in circuit opening adjustment; Fig. 5 is a diagrammatic view illustrating the principle upon which the switch operates; and Fig. 6

is a sectional view on line 6-6 of Fig. 1.

The switch structure illustrated includesa cup-shaped metallic casing member 1 1928. Serial No. 275,352.

whose end wall engages the body portion 2 I of amounting plate 3 and has an annular shoulder'4 which is confined between the body portion 2 of the plate 3 and the flange 5 upon the hollow cylindrical extension '6 of the plate. A disc of insulation 7 closes the cup, this disc being held against the rim of the cup by means of clips 8 which enter recesses in the disc and are clinched over the disc. Two metallic current conducting contact posts 9 and 10 are disposed within the casing, these posts being mounted up-:

on the insulating disc 7 and being provided with binding screws 11 and 12 upon the, exterior side'of the disc 7 for securing the circuit wires 13 and 14 in mechanical and electrical connection with said contact posts 9 and 10. Saidposts are adapted to be simultaneously engaged by a metallic bridging plate 15 whereby the circuit containing said posts may be closed. -This' bridging plate is secured by means of a stirrupor strap 16 in firm mechanical assembly with a spring barrel17 that is made of insulating material. Said bridging plate is secured &2 against the cylindrical side of said spring barrel 17 and has an angular extension which laps the closed end of said spring barrel and terminates in a fulcrum end '18 which is received within a recess 19 that is 80.. formed-upon the-inner face of the disc 7, such disc thus constituting an abutment up-' on which the member 15 has a substantially fixed fulcrum, though-the invention is notto be limited to such a fulcrum.

The spring barrel 17 is lined by a metallic tubular member 20 which is formed with an inturned shoulder 21 at the end'thereof which isremote from the closed endof said barrel. A plunger 22 has a reduced portion 991 which is surrounded by the shoulder 21- and has a base portion which is within the barrel lining 20, this base portion being sufficiently large to prevent the totaldischarge. of the plunger 22 from said barrel. A coiled 951 spring 23 is located within the spring barrel 17 and its lining 20, this coiled "spring pressing, at its right hand end, against the closed end of the barrel 17 and, at its left hand end, against the plunger 22. The 109 structure which is inclusive of the parts 15, 16, 17, 18, 20, 21 and 22 constitutes an expansible and contractible resilient member aving one abutment in the form of the disc 7. v

The outer end of the plunger 22 is received within the wide slot 24:- which is formed within the hub 25 of the handle 26, this hub constituting one of the abutments of the device of my invention. The base of the slot 24 has an extended abutment surface 27 which is diagrammatically illustrated in Fig. 5. The handle has two shaft portion 28 by which it is journaled in the mounting portion. As illustrated most clearly in Fig. 3, the handle may readily be turned upon the axis furnished by the shaft portions 28 merely by pressure exerted by a finger or thumb. The axis of turning movement for the handle which'is furnished by the shaft portions 28 and the handle 26 is between the fiat surface 27 and the abutment at 18. .The extent to which the handle may be turned is limited by the engagement thereof with the outer or base portion of the cylindrical mounting portion 6. The straight line including the axis of the shaft portions 28 and the fulcrum axis at 18, 19 is midway between the two alternative lines of pressure of the aforesaid resilient member which are effective when the handle is in its uppermost position and lowermost position and in each of which positions the surface 27 is oblique to said line of pressure. To bring the aforesaid expansible member from either alternative position to the other, the abutment 25 is positively swung upon its axis by the operator until the axis or line of pressure of the spring '23 is shifted sufliciently to the other side of the line joining the fulcra at 28 and 18, from the side previously occupied by this line of pressure, to cause the outer end of plunger 22 to quickly slide along the abutment surface 27 to bring the switch into its alternative adjustment. As illustrated, the switch is not only snapped open to avoid arcing, but

with the contractible resilient member when the adjustable abutment is being moved to remove its extended abutment surface from one obtuse direction and partially toward the other obtuse direction whereupon the resilient contractible member expands and turns. to snap the adjustable abutment" throughout the balance of its movement.

Changes may be made without departing from my invention.

Having thus described my invention, I claim:

Operating mechanism for an electric snap switch including an expansible and contractible resilient member and two abutments between which said. member is disposed, one of said abutments having an extended abutment surface along whiclrthe engaging end of said 'contractible member may slide, this abutment being adjustable to cause its said surface to be obtuse to the line of pressure of said resilient member and in two directions alternately upon opposite sides of said line of pressure, the expansible and contractible member bein fulcrumed on the other abutment, said v extended abutment surface being shaped to escapeturning engagement with said con-' tra'ctible resilient member when the adjustable abutment is being moved to remove the extended abutment surface from one obtuse I direction and partially toward the other obtuse direction whereupon the resilient contractible member expands and turns 'to snap the adjustable abutment throughout the balance of its movement.

In witness whereof, I hereunto subscribe my name.

JOHN H. NELSON.

is also snapped closed, though the inventionis not to be thus limited. It will be observed *that the pivotal axis or fulcrum of the abutment 25 is between the abutment surface 27 and the fulcrum at 18, 19, whereby the switch contacts are maintained in firm engagement during. the transition from circuit closing condition to the snappin circuit opening operation. While the ulcra at 25 and 18 are desirably in substantially fixed relation to each other and the circuit changing adjustments are effected by the expansible and contractible resilient; member which has been described, the invention is not to be thus restricted.

From the foregoing it will be observed that theextended abutment surface 27.is so shaped as to escape turning engagement 

